Effect of bioaugmentation using Clostridium butyricum on the start-up and the performance of continuous biohydrogen production

• Published in: Bioresource technology 2022-12, Vol.366, p.128181-128181, Article 128181
• Main Authors: Sim, Young-Bo, Yang, Jisu, Kim, Saint Moon, Joo, Hwan-Hong, Jung, Ju-Hyeong, Kim, Do-Hyung, Kim, Sang-Hyoun
• Format: Article
• Language: English
• Subjects: Bioaugmentation; Biohydrogen; Clostridium butyricium; Dark fermentation; Dynamic membrane bioreactor
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2022.128181

[Display omitted] •Heat-treated sludge with Clostridium butyricum produced H2 at 58.57 ± 5.03 L/L-d.•Sludge-originated H2-producers rather than C. butyricum dominated the grown culture.•C. butyricum prevented the growth of Streptococcus, Lactobacillus and Megasphaera.•Initial abundance of Clostridium over 71.3% is recommended for a continuous culture. This study aimed to mitigate the instability in the start-up and continuous performance of dark fermentative biohydrogen production using heat-treated sludge by the addition of an exogenous H2-producing strain. Continuous fermentation augmented with Clostridium butyricum showed the highest average biohydrogen production rate (HPR) as 50.35 ± 2.56 and 58.57 ± 5.03 L/L-d with H2-producing butyric and acetic acid pathways, whereas the fermenters without bioaugmentation showed the termination of biohydrogen production in 3 days of continuous operation with non H2-producing lactic acid pathway and H2-consuming propionic acid pathway. The bioaugmentation blocked the growth of the competitors for hexose such as Streptococcus, Lactobacillus and Megasphaera, and provided H2-producer dominated microbiome with not only Clostridium butyricum, but also Clostridium puniceum and Clostridium neuense originated from heat-treated sludge. Bioaugmentation of a H2-producing strain would be a reliable dissemination strategy for dark fermentative biohydrogen production by minimizing the influence of seed sludge population.